Perhaps you should try some spelling variations:
integration efforts » international efforts, conservation efforts
firms irrigation » farm irrigation, field irrigation, from irrigation
test integration » text integration, test cointegration, et integration
supply firms » supply farm, supply reforms, support firms
supply test » supply west, supply cost, supply 21st
systems. » system.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply firms irrigation systems. ) OR ( supply test integration efforts. ))~.
• Adding a wildcard symbol may retrieve word variants: (( supply firms irrigation systems. ) or ( supply test integration efforts. ))*.